Readers may not be aware of it but large part of NMEA2000 are based on ISO 11783 (Tractors and machinery for agriculture and forestry -- Serial control and communications data network.) In particular the following layers of the OSI model:
· Data Link Layer. Defined by ISO 11783-3 with additional requirements specified by the N2K standard
· Network Management. Defined by ISO 11783-5 with additional requirements specified by the N2K standard
A good overview of ISO 11783 is contained in the following lecture notes by Marvin Stone of Oklahoma State University who was on the committee which originally developed N2K
http://biosystems.okstat...e_13/J1939_ISO11783.ppt